What are the Big 8 universities in Australia?

Could you please clarify what the "Big 8 universities in Australia" are? Are these specific institutions that are widely recognized for their academic excellence, research capabilities, or perhaps their reputation in the field of finance and cryptocurrency? Additionally, is there a particular ranking system or criteria that defines these universities as part of the "Big 8" in Australia? I'm eager to learn more about these prestigious institutions and how they contribute to the Australian education landscape.